Improvement in master-key locks



T. SLAIGHT.

Master-Key Lacks.

Patented Dec.8,1874.

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KNVENTUH- fa/@JM WITNESSES- UNITED STATES PATENT OFFICE.

THOMAS SLAIGHT, OF NEWARK, NEW JERSEY.

IMPROVEMENT IN MASTER-KEY LOCKS.

Specification forming part of Letters Patent No. 157,643, dated December8, 1874; application filed July 14, 1874.

To all whom it may concern:

Be it known that I, THOMAS SLAIGIIT, of the city of Newark, in thecounty of Essex and State of New Jersey, have invented certain new anduseful Improvements in Looks, of which the following is a specification:

This invention relates to the adaptation of that class of locks'commonly called cylinderlocks to the reception `of master keys, wherebyany number of such locks, each one having a different subordinate key,can be opened by one master-key; and consists in so slotting the slidingplates of each lock actuated by a different subordinate key as tospecially adapt it to be opened by a master-key common to any number ofsimilar locks.

In the accompanying drawing is illustrated a cylinder-lock combining myimprovements, in which the cylinder B is provided with a slotted post,E, which conta-ins a number of sliding plates, b, of varying lengths andthickY nesses, which operate in conjunction Y with other sliding plates,c, contained in a suitable box or case, F, inside of the lock-case, andin juxtaposition with the slotted post E. so that the ends ofthe slidingplates b and c, abutting against each other, must each present a smoothand even surface, in order that the post E may be made to rotate whenthe key is inserted to unlock the lock.

It will be obvious that an indefinite number of locks may be made, eachrequiring` a separate key to unlock it, by simply changing the relativeposition of the sliding plates b and c, or in varying their lengths orthicknesses, or both, as a key must be fitted and adapted to each andevery change.

The master-key is constructed to lit into the same key-hole as thesubordinate key, and

into transverse slotsV d cut into the sliding plates b, common to anduniform in all the locks designed to be operated by such masterkey,substantially as shown, so that the sliding plates are forced into thesame relative positions in unlocking by the one key as by the other.

lt is obvious that a master-key mayin this manner be adapted as well tocylinder-locks having sliding pins as to those having sliding plates.

I do not claim the sliding bolt or latching mechanism connected theretoshown. in the drawing, as those features already form the subject of apatent granted to me on the 6th day of November, 1860, and extended onthe 6th day of November, 1674 5 they are only here introduced to showthe adaptation of the invention herein claimed to such locks. Nor do Iclaim the special devices shown constituting this lock a cylindenlock,such devices being likewise shown to illustrate the adaptation of myinvention toa complete working lock 5 but, as my invention,

I claim- A cylinder-lock having sliding plates b, provided with slots d,whereby any number of said locks, while each one may have a differentsubordinate key, are adapted to be opened by 011e and the samemasterkey.l in the manner substantially as described and set forth.

In testimony that I claim the foregoing as my own invention I aftixhereto my signature in presence of two witnesses.

THOS. SLAIGHT.

Witnesses:

GEO. H. WILSON, GEO. W. FRANCIS.

